meanwhile in a playground not a million miles away and sometimes frequented by me and my kids…

This is a heath goanna from Kangaroo Island. Although they do scramble up drains in search of rainwater and sniff around eskies and dinner tables in manners you would consider rather forward in another guest, they are not venomous and are kind of cool to have around. Also, it is not unreasonable to see one while you are living in the scrub, and you can be fairly sure that when you return to more settled establishments, they will be leaving you alone.